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Comparing AnyEvent/lib/AnyEvent/Handle.pm (file contents):
Revision 1.81 by root, Wed Aug 20 12:37:21 2008 UTC vs.
Revision 1.118 by root, Thu Feb 12 17:33:38 2009 UTC

14 14
15AnyEvent::Handle - non-blocking I/O on file handles via AnyEvent 15AnyEvent::Handle - non-blocking I/O on file handles via AnyEvent
16 16
17=cut 17=cut
18 18
19our $VERSION = 4.231; 19our $VERSION = 4.34;
20 20
21=head1 SYNOPSIS 21=head1 SYNOPSIS
22 22
23 use AnyEvent; 23 use AnyEvent;
24 use AnyEvent::Handle; 24 use AnyEvent::Handle;
27 27
28 my $handle = 28 my $handle =
29 AnyEvent::Handle->new ( 29 AnyEvent::Handle->new (
30 fh => \*STDIN, 30 fh => \*STDIN,
31 on_eof => sub { 31 on_eof => sub {
32 $cv->broadcast; 32 $cv->send;
33 }, 33 },
34 ); 34 );
35 35
36 # send some request line 36 # send some request line
37 $handle->push_write ("getinfo\015\012"); 37 $handle->push_write ("getinfo\015\012");
49 49
50This module is a helper module to make it easier to do event-based I/O on 50This module is a helper module to make it easier to do event-based I/O on
51filehandles. For utility functions for doing non-blocking connects and accepts 51filehandles. For utility functions for doing non-blocking connects and accepts
52on sockets see L<AnyEvent::Util>. 52on sockets see L<AnyEvent::Util>.
53 53
54The L<AnyEvent::Intro> tutorial contains some well-documented
55AnyEvent::Handle examples.
56
54In the following, when the documentation refers to of "bytes" then this 57In the following, when the documentation refers to of "bytes" then this
55means characters. As sysread and syswrite are used for all I/O, their 58means characters. As sysread and syswrite are used for all I/O, their
56treatment of characters applies to this module as well. 59treatment of characters applies to this module as well.
57 60
58All callbacks will be invoked with the handle object as their first 61All callbacks will be invoked with the handle object as their first
70 73
71=item fh => $filehandle [MANDATORY] 74=item fh => $filehandle [MANDATORY]
72 75
73The filehandle this L<AnyEvent::Handle> object will operate on. 76The filehandle this L<AnyEvent::Handle> object will operate on.
74 77
75NOTE: The filehandle will be set to non-blocking (using 78NOTE: The filehandle will be set to non-blocking mode (using
76AnyEvent::Util::fh_nonblocking). 79C<AnyEvent::Util::fh_nonblocking>) by the constructor and needs to stay in
80that mode.
77 81
78=item on_eof => $cb->($handle) 82=item on_eof => $cb->($handle)
79 83
80Set the callback to be called when an end-of-file condition is detected, 84Set the callback to be called when an end-of-file condition is detected,
81i.e. in the case of a socket, when the other side has closed the 85i.e. in the case of a socket, when the other side has closed the
82connection cleanly. 86connection cleanly.
83 87
88For sockets, this just means that the other side has stopped sending data,
89you can still try to write data, and, in fact, one can return from the EOF
90callback and continue writing data, as only the read part has been shut
91down.
92
84While not mandatory, it is I<highly> recommended to set an eof callback, 93While not mandatory, it is I<highly> recommended to set an EOF callback,
85otherwise you might end up with a closed socket while you are still 94otherwise you might end up with a closed socket while you are still
86waiting for data. 95waiting for data.
87 96
88If an EOF condition has been detected but no C<on_eof> callback has been 97If an EOF condition has been detected but no C<on_eof> callback has been
89set, then a fatal error will be raised with C<$!> set to <0>. 98set, then a fatal error will be raised with C<$!> set to <0>.
93This is the error callback, which is called when, well, some error 102This is the error callback, which is called when, well, some error
94occured, such as not being able to resolve the hostname, failure to 103occured, such as not being able to resolve the hostname, failure to
95connect or a read error. 104connect or a read error.
96 105
97Some errors are fatal (which is indicated by C<$fatal> being true). On 106Some errors are fatal (which is indicated by C<$fatal> being true). On
98fatal errors the handle object will be shut down and will not be 107fatal errors the handle object will be shut down and will not be usable
108(but you are free to look at the current C<< ->rbuf >>). Examples of fatal
109errors are an EOF condition with active (but unsatisifable) read watchers
110(C<EPIPE>) or I/O errors.
111
99usable. Non-fatal errors can be retried by simply returning, but it is 112Non-fatal errors can be retried by simply returning, but it is recommended
100recommended to simply ignore this parameter and instead abondon the handle 113to simply ignore this parameter and instead abondon the handle object
101object when this callback is invoked. 114when this callback is invoked. Examples of non-fatal errors are timeouts
115C<ETIMEDOUT>) or badly-formatted data (C<EBADMSG>).
102 116
103On callback entrance, the value of C<$!> contains the operating system 117On callback entrance, the value of C<$!> contains the operating system
104error (or C<ENOSPC>, C<EPIPE>, C<ETIMEDOUT> or C<EBADMSG>). 118error (or C<ENOSPC>, C<EPIPE>, C<ETIMEDOUT> or C<EBADMSG>).
105 119
106While not mandatory, it is I<highly> recommended to set this callback, as 120While not mandatory, it is I<highly> recommended to set this callback, as
113and no read request is in the queue (unlike read queue callbacks, this 127and no read request is in the queue (unlike read queue callbacks, this
114callback will only be called when at least one octet of data is in the 128callback will only be called when at least one octet of data is in the
115read buffer). 129read buffer).
116 130
117To access (and remove data from) the read buffer, use the C<< ->rbuf >> 131To access (and remove data from) the read buffer, use the C<< ->rbuf >>
118method or access the C<$handle->{rbuf}> member directly. 132method or access the C<$handle->{rbuf}> member directly. Note that you
133must not enlarge or modify the read buffer, you can only remove data at
134the beginning from it.
119 135
120When an EOF condition is detected then AnyEvent::Handle will first try to 136When an EOF condition is detected then AnyEvent::Handle will first try to
121feed all the remaining data to the queued callbacks and C<on_read> before 137feed all the remaining data to the queued callbacks and C<on_read> before
122calling the C<on_eof> callback. If no progress can be made, then a fatal 138calling the C<on_eof> callback. If no progress can be made, then a fatal
123error will be raised (with C<$!> set to C<EPIPE>). 139error will be raised (with C<$!> set to C<EPIPE>).
138=item timeout => $fractional_seconds 154=item timeout => $fractional_seconds
139 155
140If non-zero, then this enables an "inactivity" timeout: whenever this many 156If non-zero, then this enables an "inactivity" timeout: whenever this many
141seconds pass without a successful read or write on the underlying file 157seconds pass without a successful read or write on the underlying file
142handle, the C<on_timeout> callback will be invoked (and if that one is 158handle, the C<on_timeout> callback will be invoked (and if that one is
143missing, an C<ETIMEDOUT> error will be raised). 159missing, a non-fatal C<ETIMEDOUT> error will be raised).
144 160
145Note that timeout processing is also active when you currently do not have 161Note that timeout processing is also active when you currently do not have
146any outstanding read or write requests: If you plan to keep the connection 162any outstanding read or write requests: If you plan to keep the connection
147idle then you should disable the timout temporarily or ignore the timeout 163idle then you should disable the timout temporarily or ignore the timeout
148in the C<on_timeout> callback. 164in the C<on_timeout> callback, in which case AnyEvent::Handle will simply
165restart the timeout.
149 166
150Zero (the default) disables this timeout. 167Zero (the default) disables this timeout.
151 168
152=item on_timeout => $cb->($handle) 169=item on_timeout => $cb->($handle)
153 170
157 174
158=item rbuf_max => <bytes> 175=item rbuf_max => <bytes>
159 176
160If defined, then a fatal error will be raised (with C<$!> set to C<ENOSPC>) 177If defined, then a fatal error will be raised (with C<$!> set to C<ENOSPC>)
161when the read buffer ever (strictly) exceeds this size. This is useful to 178when the read buffer ever (strictly) exceeds this size. This is useful to
162avoid denial-of-service attacks. 179avoid some forms of denial-of-service attacks.
163 180
164For example, a server accepting connections from untrusted sources should 181For example, a server accepting connections from untrusted sources should
165be configured to accept only so-and-so much data that it cannot act on 182be configured to accept only so-and-so much data that it cannot act on
166(for example, when expecting a line, an attacker could send an unlimited 183(for example, when expecting a line, an attacker could send an unlimited
167amount of data without a callback ever being called as long as the line 184amount of data without a callback ever being called as long as the line
168isn't finished). 185isn't finished).
169 186
170=item autocork => <boolean> 187=item autocork => <boolean>
171 188
172When disabled (the default), then C<push_write> will try to immediately 189When disabled (the default), then C<push_write> will try to immediately
173write the data to the handle if possible. This avoids having to register 190write the data to the handle, if possible. This avoids having to register
174a write watcher and wait for the next event loop iteration, but can be 191a write watcher and wait for the next event loop iteration, but can
175inefficient if you write multiple small chunks (this disadvantage is 192be inefficient if you write multiple small chunks (on the wire, this
176usually avoided by your kernel's nagle algorithm, see C<low_delay>). 193disadvantage is usually avoided by your kernel's nagle algorithm, see
194C<no_delay>, but this option can save costly syscalls).
177 195
178When enabled, then writes will always be queued till the next event loop 196When enabled, then writes will always be queued till the next event loop
179iteration. This is efficient when you do many small writes per iteration, 197iteration. This is efficient when you do many small writes per iteration,
180but less efficient when you do a single write only. 198but less efficient when you do a single write only per iteration (or when
199the write buffer often is full). It also increases write latency.
181 200
182=item no_delay => <boolean> 201=item no_delay => <boolean>
183 202
184When doing small writes on sockets, your operating system kernel might 203When doing small writes on sockets, your operating system kernel might
185wait a bit for more data before actually sending it out. This is called 204wait a bit for more data before actually sending it out. This is called
186the Nagle algorithm, and usually it is beneficial. 205the Nagle algorithm, and usually it is beneficial.
187 206
188In some situations you want as low a delay as possible, which cna be 207In some situations you want as low a delay as possible, which can be
189accomplishd by setting this option to true. 208accomplishd by setting this option to a true value.
190 209
191The default is your opertaing system's default behaviour, this option 210The default is your opertaing system's default behaviour (most likely
192explicitly enables or disables it, if possible. 211enabled), this option explicitly enables or disables it, if possible.
193 212
194=item read_size => <bytes> 213=item read_size => <bytes>
195 214
196The default read block size (the amount of bytes this module will try to read 215The default read block size (the amount of bytes this module will
197during each (loop iteration). Default: C<8192>. 216try to read during each loop iteration, which affects memory
217requirements). Default: C<8192>.
198 218
199=item low_water_mark => <bytes> 219=item low_water_mark => <bytes>
200 220
201Sets the amount of bytes (default: C<0>) that make up an "empty" write 221Sets the amount of bytes (default: C<0>) that make up an "empty" write
202buffer: If the write reaches this size or gets even samller it is 222buffer: If the write reaches this size or gets even samller it is
203considered empty. 223considered empty.
204 224
225Sometimes it can be beneficial (for performance reasons) to add data to
226the write buffer before it is fully drained, but this is a rare case, as
227the operating system kernel usually buffers data as well, so the default
228is good in almost all cases.
229
205=item linger => <seconds> 230=item linger => <seconds>
206 231
207If non-zero (default: C<3600>), then the destructor of the 232If non-zero (default: C<3600>), then the destructor of the
208AnyEvent::Handle object will check wether there is still outstanding write 233AnyEvent::Handle object will check whether there is still outstanding
209data and will install a watcher that will write out this data. No errors 234write data and will install a watcher that will write this data to the
210will be reported (this mostly matches how the operating system treats 235socket. No errors will be reported (this mostly matches how the operating
211outstanding data at socket close time). 236system treats outstanding data at socket close time).
212 237
213This will not work for partial TLS data that could not yet been 238This will not work for partial TLS data that could not be encoded
214encoded. This data will be lost. 239yet. This data will be lost. Calling the C<stoptls> method in time might
240help.
215 241
216=item tls => "accept" | "connect" | Net::SSLeay::SSL object 242=item tls => "accept" | "connect" | Net::SSLeay::SSL object
217 243
218When this parameter is given, it enables TLS (SSL) mode, that means it 244When this parameter is given, it enables TLS (SSL) mode, that means
219will start making tls handshake and will transparently encrypt/decrypt 245AnyEvent will start a TLS handshake as soon as the conenction has been
220data. 246established and will transparently encrypt/decrypt data afterwards.
221 247
222TLS mode requires Net::SSLeay to be installed (it will be loaded 248TLS mode requires Net::SSLeay to be installed (it will be loaded
223automatically when you try to create a TLS handle). 249automatically when you try to create a TLS handle): this module doesn't
250have a dependency on that module, so if your module requires it, you have
251to add the dependency yourself.
224 252
225For the TLS server side, use C<accept>, and for the TLS client side of a 253Unlike TCP, TLS has a server and client side: for the TLS server side, use
226connection, use C<connect> mode. 254C<accept>, and for the TLS client side of a connection, use C<connect>
255mode.
227 256
228You can also provide your own TLS connection object, but you have 257You can also provide your own TLS connection object, but you have
229to make sure that you call either C<Net::SSLeay::set_connect_state> 258to make sure that you call either C<Net::SSLeay::set_connect_state>
230or C<Net::SSLeay::set_accept_state> on it before you pass it to 259or C<Net::SSLeay::set_accept_state> on it before you pass it to
231AnyEvent::Handle. 260AnyEvent::Handle.
232 261
262B<IMPORTANT:> since Net::SSLeay "objects" are really only integers,
263passing in the wrong integer will lead to certain crash. This most often
264happens when one uses a stylish C<< tls => 1 >> and is surprised about the
265segmentation fault.
266
233See the C<starttls> method if you need to start TLS negotiation later. 267See the C<< ->starttls >> method for when need to start TLS negotiation later.
234 268
235=item tls_ctx => $ssl_ctx 269=item tls_ctx => $ssl_ctx
236 270
237Use the given Net::SSLeay::CTX object to create the new TLS connection 271Use the given C<Net::SSLeay::CTX> object to create the new TLS connection
238(unless a connection object was specified directly). If this parameter is 272(unless a connection object was specified directly). If this parameter is
239missing, then AnyEvent::Handle will use C<AnyEvent::Handle::TLS_CTX>. 273missing, then AnyEvent::Handle will use C<AnyEvent::Handle::TLS_CTX>.
240 274
241=item json => JSON or JSON::XS object 275=item json => JSON or JSON::XS object
242 276
243This is the json coder object used by the C<json> read and write types. 277This is the json coder object used by the C<json> read and write types.
244 278
245If you don't supply it, then AnyEvent::Handle will create and use a 279If you don't supply it, then AnyEvent::Handle will create and use a
246suitable one, which will write and expect UTF-8 encoded JSON texts. 280suitable one (on demand), which will write and expect UTF-8 encoded JSON
281texts.
247 282
248Note that you are responsible to depend on the JSON module if you want to 283Note that you are responsible to depend on the JSON module if you want to
249use this functionality, as AnyEvent does not have a dependency itself. 284use this functionality, as AnyEvent does not have a dependency itself.
250 285
251=item filter_r => $cb
252
253=item filter_w => $cb
254
255These exist, but are undocumented at this time.
256
257=back 286=back
258 287
259=cut 288=cut
260 289
261sub new { 290sub new {
265 294
266 $self->{fh} or Carp::croak "mandatory argument fh is missing"; 295 $self->{fh} or Carp::croak "mandatory argument fh is missing";
267 296
268 AnyEvent::Util::fh_nonblocking $self->{fh}, 1; 297 AnyEvent::Util::fh_nonblocking $self->{fh}, 1;
269 298
270 if ($self->{tls}) {
271 require Net::SSLeay;
272 $self->starttls (delete $self->{tls}, delete $self->{tls_ctx}); 299 $self->starttls (delete $self->{tls}, delete $self->{tls_ctx})
273 } 300 if $self->{tls};
274 301
275 $self->{_activity} = AnyEvent->now; 302 $self->{_activity} = AnyEvent->now;
276 $self->_timeout; 303 $self->_timeout;
277 304
278 $self->on_drain (delete $self->{on_drain}) if exists $self->{on_drain}; 305 $self->on_drain (delete $self->{on_drain}) if exists $self->{on_drain};
290 delete $self->{_tw}; 317 delete $self->{_tw};
291 delete $self->{_rw}; 318 delete $self->{_rw};
292 delete $self->{_ww}; 319 delete $self->{_ww};
293 delete $self->{fh}; 320 delete $self->{fh};
294 321
295 $self->stoptls; 322 &_freetls;
323
324 delete $self->{on_read};
325 delete $self->{_queue};
296} 326}
297 327
298sub _error { 328sub _error {
299 my ($self, $errno, $fatal) = @_; 329 my ($self, $errno, $fatal) = @_;
300 330
303 333
304 $! = $errno; 334 $! = $errno;
305 335
306 if ($self->{on_error}) { 336 if ($self->{on_error}) {
307 $self->{on_error}($self, $fatal); 337 $self->{on_error}($self, $fatal);
308 } else { 338 } elsif ($self->{fh}) {
309 Carp::croak "AnyEvent::Handle uncaught error: $!"; 339 Carp::croak "AnyEvent::Handle uncaught error: $!";
310 } 340 }
311} 341}
312 342
313=item $fh = $handle->fh 343=item $fh = $handle->fh
314 344
315This method returns the file handle of the L<AnyEvent::Handle> object. 345This method returns the file handle used to create the L<AnyEvent::Handle> object.
316 346
317=cut 347=cut
318 348
319sub fh { $_[0]{fh} } 349sub fh { $_[0]{fh} }
320 350
338 $_[0]{on_eof} = $_[1]; 368 $_[0]{on_eof} = $_[1];
339} 369}
340 370
341=item $handle->on_timeout ($cb) 371=item $handle->on_timeout ($cb)
342 372
343Replace the current C<on_timeout> callback, or disables the callback 373Replace the current C<on_timeout> callback, or disables the callback (but
344(but not the timeout) if C<$cb> = C<undef>. See C<timeout> constructor 374not the timeout) if C<$cb> = C<undef>. See the C<timeout> constructor
345argument. 375argument and method.
346 376
347=cut 377=cut
348 378
349sub on_timeout { 379sub on_timeout {
350 $_[0]{on_timeout} = $_[1]; 380 $_[0]{on_timeout} = $_[1];
351} 381}
352 382
353=item $handle->autocork ($boolean) 383=item $handle->autocork ($boolean)
354 384
355Enables or disables the current autocork behaviour (see C<autocork> 385Enables or disables the current autocork behaviour (see C<autocork>
356constructor argument). 386constructor argument). Changes will only take effect on the next write.
357 387
358=cut 388=cut
389
390sub autocork {
391 $_[0]{autocork} = $_[1];
392}
359 393
360=item $handle->no_delay ($boolean) 394=item $handle->no_delay ($boolean)
361 395
362Enables or disables the C<no_delay> setting (see constructor argument of 396Enables or disables the C<no_delay> setting (see constructor argument of
363the same name for details). 397the same name for details).
456 my ($self, $cb) = @_; 490 my ($self, $cb) = @_;
457 491
458 $self->{on_drain} = $cb; 492 $self->{on_drain} = $cb;
459 493
460 $cb->($self) 494 $cb->($self)
461 if $cb && $self->{low_water_mark} >= length $self->{wbuf}; 495 if $cb && $self->{low_water_mark} >= (length $self->{wbuf}) + (length $self->{_tls_wbuf});
462} 496}
463 497
464=item $handle->push_write ($data) 498=item $handle->push_write ($data)
465 499
466Queues the given scalar to be written. You can push as much data as you 500Queues the given scalar to be written. You can push as much data as you
483 substr $self->{wbuf}, 0, $len, ""; 517 substr $self->{wbuf}, 0, $len, "";
484 518
485 $self->{_activity} = AnyEvent->now; 519 $self->{_activity} = AnyEvent->now;
486 520
487 $self->{on_drain}($self) 521 $self->{on_drain}($self)
488 if $self->{low_water_mark} >= length $self->{wbuf} 522 if $self->{low_water_mark} >= (length $self->{wbuf}) + (length $self->{_tls_wbuf})
489 && $self->{on_drain}; 523 && $self->{on_drain};
490 524
491 delete $self->{_ww} unless length $self->{wbuf}; 525 delete $self->{_ww} unless length $self->{wbuf};
492 } elsif ($! != EAGAIN && $! != EINTR && $! != WSAEWOULDBLOCK) { 526 } elsif ($! != EAGAIN && $! != EINTR && $! != WSAEWOULDBLOCK) {
493 $self->_error ($!, 1); 527 $self->_error ($!, 1);
517 551
518 @_ = ($WH{$type} or Carp::croak "unsupported type passed to AnyEvent::Handle::push_write") 552 @_ = ($WH{$type} or Carp::croak "unsupported type passed to AnyEvent::Handle::push_write")
519 ->($self, @_); 553 ->($self, @_);
520 } 554 }
521 555
522 if ($self->{filter_w}) { 556 if ($self->{tls}) {
523 $self->{filter_w}($self, \$_[0]); 557 $self->{_tls_wbuf} .= $_[0];
558
559 &_dotls ($self);
524 } else { 560 } else {
525 $self->{wbuf} .= $_[0]; 561 $self->{wbuf} .= $_[0];
526 $self->_drain_wbuf; 562 $self->_drain_wbuf;
527 } 563 }
528} 564}
545=cut 581=cut
546 582
547register_write_type netstring => sub { 583register_write_type netstring => sub {
548 my ($self, $string) = @_; 584 my ($self, $string) = @_;
549 585
550 sprintf "%d:%s,", (length $string), $string 586 (length $string) . ":$string,"
551}; 587};
552 588
553=item packstring => $format, $data 589=item packstring => $format, $data
554 590
555An octet string prefixed with an encoded length. The encoding C<$format> 591An octet string prefixed with an encoded length. The encoding C<$format>
729 765
730 if ( 766 if (
731 defined $self->{rbuf_max} 767 defined $self->{rbuf_max}
732 && $self->{rbuf_max} < length $self->{rbuf} 768 && $self->{rbuf_max} < length $self->{rbuf}
733 ) { 769 ) {
734 return $self->_error (&Errno::ENOSPC, 1); 770 $self->_error (&Errno::ENOSPC, 1), return;
735 } 771 }
736 772
737 while () { 773 while () {
774 # we need to use a separate tls read buffer, as we must not receive data while
775 # we are draining the buffer, and this can only happen with TLS.
776 $self->{rbuf} .= delete $self->{_tls_rbuf} if exists $self->{_tls_rbuf};
777
738 my $len = length $self->{rbuf}; 778 my $len = length $self->{rbuf};
739 779
740 if (my $cb = shift @{ $self->{_queue} }) { 780 if (my $cb = shift @{ $self->{_queue} }) {
741 unless ($cb->($self)) { 781 unless ($cb->($self)) {
742 if ($self->{_eof}) { 782 if ($self->{_eof}) {
743 # no progress can be made (not enough data and no data forthcoming) 783 # no progress can be made (not enough data and no data forthcoming)
744 $self->_error (&Errno::EPIPE, 1), last; 784 $self->_error (&Errno::EPIPE, 1), return;
745 } 785 }
746 786
747 unshift @{ $self->{_queue} }, $cb; 787 unshift @{ $self->{_queue} }, $cb;
748 last; 788 last;
749 } 789 }
757 && !@{ $self->{_queue} } # and the queue is still empty 797 && !@{ $self->{_queue} } # and the queue is still empty
758 && $self->{on_read} # but we still have on_read 798 && $self->{on_read} # but we still have on_read
759 ) { 799 ) {
760 # no further data will arrive 800 # no further data will arrive
761 # so no progress can be made 801 # so no progress can be made
762 $self->_error (&Errno::EPIPE, 1), last 802 $self->_error (&Errno::EPIPE, 1), return
763 if $self->{_eof}; 803 if $self->{_eof};
764 804
765 last; # more data might arrive 805 last; # more data might arrive
766 } 806 }
767 } else { 807 } else {
768 # read side becomes idle 808 # read side becomes idle
769 delete $self->{_rw}; 809 delete $self->{_rw} unless $self->{tls};
770 last; 810 last;
771 } 811 }
772 } 812 }
773 813
774 if ($self->{_eof}) { 814 if ($self->{_eof}) {
803 843
804=item $handle->rbuf 844=item $handle->rbuf
805 845
806Returns the read buffer (as a modifiable lvalue). 846Returns the read buffer (as a modifiable lvalue).
807 847
808You can access the read buffer directly as the C<< ->{rbuf} >> member, if 848You can access the read buffer directly as the C<< ->{rbuf} >>
809you want. 849member, if you want. However, the only operation allowed on the
850read buffer (apart from looking at it) is removing data from its
851beginning. Otherwise modifying or appending to it is not allowed and will
852lead to hard-to-track-down bugs.
810 853
811NOTE: The read buffer should only be used or modified if the C<on_read>, 854NOTE: The read buffer should only be used or modified if the C<on_read>,
812C<push_read> or C<unshift_read> methods are used. The other read methods 855C<push_read> or C<unshift_read> methods are used. The other read methods
813automatically manage the read buffer. 856automatically manage the read buffer.
814 857
1069An octet string prefixed with an encoded length. The encoding C<$format> 1112An octet string prefixed with an encoded length. The encoding C<$format>
1070uses the same format as a Perl C<pack> format, but must specify a single 1113uses the same format as a Perl C<pack> format, but must specify a single
1071integer only (only one of C<cCsSlLqQiInNvVjJw> is allowed, plus an 1114integer only (only one of C<cCsSlLqQiInNvVjJw> is allowed, plus an
1072optional C<!>, C<< < >> or C<< > >> modifier). 1115optional C<!>, C<< < >> or C<< > >> modifier).
1073 1116
1074DNS over TCP uses a prefix of C<n>, EPP uses a prefix of C<N>. 1117For example, DNS over TCP uses a prefix of C<n> (2 octet network order),
1118EPP uses a prefix of C<N> (4 octtes).
1075 1119
1076Example: read a block of data prefixed by its length in BER-encoded 1120Example: read a block of data prefixed by its length in BER-encoded
1077format (very efficient). 1121format (very efficient).
1078 1122
1079 $handle->push_read (packstring => "w", sub { 1123 $handle->push_read (packstring => "w", sub {
1109 } 1153 }
1110}; 1154};
1111 1155
1112=item json => $cb->($handle, $hash_or_arrayref) 1156=item json => $cb->($handle, $hash_or_arrayref)
1113 1157
1114Reads a JSON object or array, decodes it and passes it to the callback. 1158Reads a JSON object or array, decodes it and passes it to the
1159callback. When a parse error occurs, an C<EBADMSG> error will be raised.
1115 1160
1116If a C<json> object was passed to the constructor, then that will be used 1161If a C<json> object was passed to the constructor, then that will be used
1117for the final decode, otherwise it will create a JSON coder expecting UTF-8. 1162for the final decode, otherwise it will create a JSON coder expecting UTF-8.
1118 1163
1119This read type uses the incremental parser available with JSON version 1164This read type uses the incremental parser available with JSON version
1136 my $rbuf = \$self->{rbuf}; 1181 my $rbuf = \$self->{rbuf};
1137 1182
1138 my $json = $self->{json} ||= JSON->new->utf8; 1183 my $json = $self->{json} ||= JSON->new->utf8;
1139 1184
1140 sub { 1185 sub {
1141 my $ref = $json->incr_parse ($self->{rbuf}); 1186 my $ref = eval { $json->incr_parse ($self->{rbuf}) };
1142 1187
1143 if ($ref) { 1188 if ($ref) {
1144 $self->{rbuf} = $json->incr_text; 1189 $self->{rbuf} = $json->incr_text;
1145 $json->incr_text = ""; 1190 $json->incr_text = "";
1146 $cb->($self, $ref); 1191 $cb->($self, $ref);
1147 1192
1148 1 1193 1
1194 } elsif ($@) {
1195 # error case
1196 $json->incr_skip;
1197
1198 $self->{rbuf} = $json->incr_text;
1199 $json->incr_text = "";
1200
1201 $self->_error (&Errno::EBADMSG);
1202
1203 ()
1149 } else { 1204 } else {
1150 $self->{rbuf} = ""; 1205 $self->{rbuf} = "";
1206
1151 () 1207 ()
1152 } 1208 }
1153 } 1209 }
1154}; 1210};
1155 1211
1232Note that AnyEvent::Handle will automatically C<start_read> for you when 1288Note that AnyEvent::Handle will automatically C<start_read> for you when
1233you change the C<on_read> callback or push/unshift a read callback, and it 1289you change the C<on_read> callback or push/unshift a read callback, and it
1234will automatically C<stop_read> for you when neither C<on_read> is set nor 1290will automatically C<stop_read> for you when neither C<on_read> is set nor
1235there are any read requests in the queue. 1291there are any read requests in the queue.
1236 1292
1293These methods will have no effect when in TLS mode (as TLS doesn't support
1294half-duplex connections).
1295
1237=cut 1296=cut
1238 1297
1239sub stop_read { 1298sub stop_read {
1240 my ($self) = @_; 1299 my ($self) = @_;
1241 1300
1242 delete $self->{_rw}; 1301 delete $self->{_rw} unless $self->{tls};
1243} 1302}
1244 1303
1245sub start_read { 1304sub start_read {
1246 my ($self) = @_; 1305 my ($self) = @_;
1247 1306
1248 unless ($self->{_rw} || $self->{_eof}) { 1307 unless ($self->{_rw} || $self->{_eof}) {
1249 Scalar::Util::weaken $self; 1308 Scalar::Util::weaken $self;
1250 1309
1251 $self->{_rw} = AnyEvent->io (fh => $self->{fh}, poll => "r", cb => sub { 1310 $self->{_rw} = AnyEvent->io (fh => $self->{fh}, poll => "r", cb => sub {
1252 my $rbuf = $self->{filter_r} ? \my $buf : \$self->{rbuf}; 1311 my $rbuf = \($self->{tls} ? my $buf : $self->{rbuf});
1253 my $len = sysread $self->{fh}, $$rbuf, $self->{read_size} || 8192, length $$rbuf; 1312 my $len = sysread $self->{fh}, $$rbuf, $self->{read_size} || 8192, length $$rbuf;
1254 1313
1255 if ($len > 0) { 1314 if ($len > 0) {
1256 $self->{_activity} = AnyEvent->now; 1315 $self->{_activity} = AnyEvent->now;
1257 1316
1258 $self->{filter_r} 1317 if ($self->{tls}) {
1259 ? $self->{filter_r}($self, $rbuf) 1318 Net::SSLeay::BIO_write ($self->{_rbio}, $$rbuf);
1260 : $self->{_in_drain} || $self->_drain_rbuf; 1319
1320 &_dotls ($self);
1321 } else {
1322 $self->_drain_rbuf unless $self->{_in_drain};
1323 }
1261 1324
1262 } elsif (defined $len) { 1325 } elsif (defined $len) {
1263 delete $self->{_rw}; 1326 delete $self->{_rw};
1264 $self->{_eof} = 1; 1327 $self->{_eof} = 1;
1265 $self->_drain_rbuf unless $self->{_in_drain}; 1328 $self->_drain_rbuf unless $self->{_in_drain};
1269 } 1332 }
1270 }); 1333 });
1271 } 1334 }
1272} 1335}
1273 1336
1337# poll the write BIO and send the data if applicable
1274sub _dotls { 1338sub _dotls {
1275 my ($self) = @_; 1339 my ($self) = @_;
1276 1340
1277 my $buf; 1341 my $tmp;
1278 1342
1279 if (length $self->{_tls_wbuf}) { 1343 if (length $self->{_tls_wbuf}) {
1280 while ((my $len = Net::SSLeay::write ($self->{tls}, $self->{_tls_wbuf})) > 0) { 1344 while (($tmp = Net::SSLeay::write ($self->{tls}, $self->{_tls_wbuf})) > 0) {
1281 substr $self->{_tls_wbuf}, 0, $len, ""; 1345 substr $self->{_tls_wbuf}, 0, $tmp, "";
1282 } 1346 }
1283 } 1347 }
1284 1348
1285 if (length ($buf = Net::SSLeay::BIO_read ($self->{_wbio}))) {
1286 $self->{wbuf} .= $buf;
1287 $self->_drain_wbuf;
1288 }
1289
1290 while (defined ($buf = Net::SSLeay::read ($self->{tls}))) { 1349 while (defined ($tmp = Net::SSLeay::read ($self->{tls}))) {
1291 if (length $buf) { 1350 unless (length $tmp) {
1292 $self->{rbuf} .= $buf;
1293 $self->_drain_rbuf unless $self->{_in_drain};
1294 } else {
1295 # let's treat SSL-eof as we treat normal EOF 1351 # let's treat SSL-eof as we treat normal EOF
1352 delete $self->{_rw};
1296 $self->{_eof} = 1; 1353 $self->{_eof} = 1;
1297 $self->_shutdown; 1354 &_freetls;
1298 return;
1299 } 1355 }
1300 }
1301 1356
1357 $self->{_tls_rbuf} .= $tmp;
1358 $self->_drain_rbuf unless $self->{_in_drain};
1359 $self->{tls} or return; # tls session might have gone away in callback
1360 }
1361
1302 my $err = Net::SSLeay::get_error ($self->{tls}, -1); 1362 $tmp = Net::SSLeay::get_error ($self->{tls}, -1);
1303 1363
1304 if ($err!= Net::SSLeay::ERROR_WANT_READ ()) { 1364 if ($tmp != Net::SSLeay::ERROR_WANT_READ ()) {
1305 if ($err == Net::SSLeay::ERROR_SYSCALL ()) { 1365 if ($tmp == Net::SSLeay::ERROR_SYSCALL ()) {
1306 return $self->_error ($!, 1); 1366 return $self->_error ($!, 1);
1307 } elsif ($err == Net::SSLeay::ERROR_SSL ()) { 1367 } elsif ($tmp == Net::SSLeay::ERROR_SSL ()) {
1308 return $self->_error (&Errno::EIO, 1); 1368 return $self->_error (&Errno::EIO, 1);
1309 } 1369 }
1310 1370
1311 # all others are fine for our purposes 1371 # all other errors are fine for our purposes
1372 }
1373
1374 while (length ($tmp = Net::SSLeay::BIO_read ($self->{_wbio}))) {
1375 $self->{wbuf} .= $tmp;
1376 $self->_drain_wbuf;
1312 } 1377 }
1313} 1378}
1314 1379
1315=item $handle->starttls ($tls[, $tls_ctx]) 1380=item $handle->starttls ($tls[, $tls_ctx])
1316 1381
1326 1391
1327The TLS connection object will end up in C<< $handle->{tls} >> after this 1392The TLS connection object will end up in C<< $handle->{tls} >> after this
1328call and can be used or changed to your liking. Note that the handshake 1393call and can be used or changed to your liking. Note that the handshake
1329might have already started when this function returns. 1394might have already started when this function returns.
1330 1395
1396If it an error to start a TLS handshake more than once per
1397AnyEvent::Handle object (this is due to bugs in OpenSSL).
1398
1331=cut 1399=cut
1332 1400
1333sub starttls { 1401sub starttls {
1334 my ($self, $ssl, $ctx) = @_; 1402 my ($self, $ssl, $ctx) = @_;
1335 1403
1336 $self->stoptls; 1404 require Net::SSLeay;
1337 1405
1406 Carp::croak "it is an error to call starttls more than once on an AnyEvent::Handle object"
1407 if $self->{tls};
1408
1338 if ($ssl eq "accept") { 1409 if ($ssl eq "accept") {
1339 $ssl = Net::SSLeay::new ($ctx || TLS_CTX ()); 1410 $ssl = Net::SSLeay::new ($ctx || TLS_CTX ());
1340 Net::SSLeay::set_accept_state ($ssl); 1411 Net::SSLeay::set_accept_state ($ssl);
1341 } elsif ($ssl eq "connect") { 1412 } elsif ($ssl eq "connect") {
1342 $ssl = Net::SSLeay::new ($ctx || TLS_CTX ()); 1413 $ssl = Net::SSLeay::new ($ctx || TLS_CTX ());
1348 # basically, this is deep magic (because SSL_read should have the same issues) 1419 # basically, this is deep magic (because SSL_read should have the same issues)
1349 # but the openssl maintainers basically said: "trust us, it just works". 1420 # but the openssl maintainers basically said: "trust us, it just works".
1350 # (unfortunately, we have to hardcode constants because the abysmally misdesigned 1421 # (unfortunately, we have to hardcode constants because the abysmally misdesigned
1351 # and mismaintained ssleay-module doesn't even offer them). 1422 # and mismaintained ssleay-module doesn't even offer them).
1352 # http://www.mail-archive.com/openssl-dev@openssl.org/msg22420.html 1423 # http://www.mail-archive.com/openssl-dev@openssl.org/msg22420.html
1424 #
1425 # in short: this is a mess.
1426 #
1427 # note that we do not try to keep the length constant between writes as we are required to do.
1428 # we assume that most (but not all) of this insanity only applies to non-blocking cases,
1429 # and we drive openssl fully in blocking mode here. Or maybe we don't - openssl seems to
1430 # have identity issues in that area.
1353 Net::SSLeay::CTX_set_mode ($self->{tls}, 1431 Net::SSLeay::CTX_set_mode ($self->{tls},
1354 (eval { local $SIG{__DIE__}; Net::SSLeay::MODE_ENABLE_PARTIAL_WRITE () } || 1) 1432 (eval { local $SIG{__DIE__}; Net::SSLeay::MODE_ENABLE_PARTIAL_WRITE () } || 1)
1355 | (eval { local $SIG{__DIE__}; Net::SSLeay::MODE_ACCEPT_MOVING_WRITE_BUFFER () } || 2)); 1433 | (eval { local $SIG{__DIE__}; Net::SSLeay::MODE_ACCEPT_MOVING_WRITE_BUFFER () } || 2));
1356 1434
1357 $self->{_rbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ()); 1435 $self->{_rbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ());
1358 $self->{_wbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ()); 1436 $self->{_wbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ());
1359 1437
1360 Net::SSLeay::set_bio ($ssl, $self->{_rbio}, $self->{_wbio}); 1438 Net::SSLeay::set_bio ($ssl, $self->{_rbio}, $self->{_wbio});
1361 1439
1362 $self->{filter_w} = sub { 1440 &_dotls; # need to trigger the initial handshake
1363 $_[0]{_tls_wbuf} .= ${$_[1]}; 1441 $self->start_read; # make sure we actually do read
1364 &_dotls;
1365 };
1366 $self->{filter_r} = sub {
1367 Net::SSLeay::BIO_write ($_[0]{_rbio}, ${$_[1]});
1368 &_dotls;
1369 };
1370} 1442}
1371 1443
1372=item $handle->stoptls 1444=item $handle->stoptls
1373 1445
1374Destroys the SSL connection, if any. Partial read or write data will be 1446Shuts down the SSL connection - this makes a proper EOF handshake by
1375lost. 1447sending a close notify to the other side, but since OpenSSL doesn't
1448support non-blocking shut downs, it is not possible to re-use the stream
1449afterwards.
1376 1450
1377=cut 1451=cut
1378 1452
1379sub stoptls { 1453sub stoptls {
1380 my ($self) = @_; 1454 my ($self) = @_;
1381 1455
1456 if ($self->{tls}) {
1457 Net::SSLeay::shutdown ($self->{tls});
1458
1459 &_dotls;
1460
1461 # we don't give a shit. no, we do, but we can't. no...
1462 # we, we... have to use openssl :/
1463 &_freetls;
1464 }
1465}
1466
1467sub _freetls {
1468 my ($self) = @_;
1469
1470 return unless $self->{tls};
1471
1382 Net::SSLeay::free (delete $self->{tls}) if $self->{tls}; 1472 Net::SSLeay::free (delete $self->{tls});
1383 1473
1384 delete $self->{_rbio}; 1474 delete @$self{qw(_rbio _wbio _tls_wbuf)};
1385 delete $self->{_wbio};
1386 delete $self->{_tls_wbuf};
1387 delete $self->{filter_r};
1388 delete $self->{filter_w};
1389} 1475}
1390 1476
1391sub DESTROY { 1477sub DESTROY {
1392 my $self = shift; 1478 my $self = shift;
1393 1479
1394 $self->stoptls; 1480 &_freetls;
1395 1481
1396 my $linger = exists $self->{linger} ? $self->{linger} : 3600; 1482 my $linger = exists $self->{linger} ? $self->{linger} : 3600;
1397 1483
1398 if ($linger && length $self->{wbuf}) { 1484 if ($linger && length $self->{wbuf}) {
1399 my $fh = delete $self->{fh}; 1485 my $fh = delete $self->{fh};
1414 @linger = (); 1500 @linger = ();
1415 }); 1501 });
1416 } 1502 }
1417} 1503}
1418 1504
1505=item $handle->destroy
1506
1507Shuts down the handle object as much as possible - this call ensures that
1508no further callbacks will be invoked and resources will be freed as much
1509as possible. You must not call any methods on the object afterwards.
1510
1511Normally, you can just "forget" any references to an AnyEvent::Handle
1512object and it will simply shut down. This works in fatal error and EOF
1513callbacks, as well as code outside. It does I<NOT> work in a read or write
1514callback, so when you want to destroy the AnyEvent::Handle object from
1515within such an callback. You I<MUST> call C<< ->destroy >> explicitly in
1516that case.
1517
1518The handle might still linger in the background and write out remaining
1519data, as specified by the C<linger> option, however.
1520
1521=cut
1522
1523sub destroy {
1524 my ($self) = @_;
1525
1526 $self->DESTROY;
1527 %$self = ();
1528}
1529
1419=item AnyEvent::Handle::TLS_CTX 1530=item AnyEvent::Handle::TLS_CTX
1420 1531
1421This function creates and returns the Net::SSLeay::CTX object used by 1532This function creates and returns the Net::SSLeay::CTX object used by
1422default for TLS mode. 1533default for TLS mode.
1423 1534
1451 } 1562 }
1452} 1563}
1453 1564
1454=back 1565=back
1455 1566
1567
1568=head1 NONFREQUENTLY ASKED QUESTIONS
1569
1570=over 4
1571
1572=item I C<undef> the AnyEvent::Handle reference inside my callback and
1573still get further invocations!
1574
1575That's because AnyEvent::Handle keeps a reference to itself when handling
1576read or write callbacks.
1577
1578It is only safe to "forget" the reference inside EOF or error callbacks,
1579from within all other callbacks, you need to explicitly call the C<<
1580->destroy >> method.
1581
1582=item I get different callback invocations in TLS mode/Why can't I pause
1583reading?
1584
1585Unlike, say, TCP, TLS connections do not consist of two independent
1586communication channels, one for each direction. Or put differently. The
1587read and write directions are not independent of each other: you cannot
1588write data unless you are also prepared to read, and vice versa.
1589
1590This can mean than, in TLS mode, you might get C<on_error> or C<on_eof>
1591callback invocations when you are not expecting any read data - the reason
1592is that AnyEvent::Handle always reads in TLS mode.
1593
1594During the connection, you have to make sure that you always have a
1595non-empty read-queue, or an C<on_read> watcher. At the end of the
1596connection (or when you no longer want to use it) you can call the
1597C<destroy> method.
1598
1599=item How do I read data until the other side closes the connection?
1600
1601If you just want to read your data into a perl scalar, the easiest way
1602to achieve this is by setting an C<on_read> callback that does nothing,
1603clearing the C<on_eof> callback and in the C<on_error> callback, the data
1604will be in C<$_[0]{rbuf}>:
1605
1606 $handle->on_read (sub { });
1607 $handle->on_eof (undef);
1608 $handle->on_error (sub {
1609 my $data = delete $_[0]{rbuf};
1610 undef $handle;
1611 });
1612
1613The reason to use C<on_error> is that TCP connections, due to latencies
1614and packets loss, might get closed quite violently with an error, when in
1615fact, all data has been received.
1616
1617It is usually better to use acknowledgements when transferring data,
1618to make sure the other side hasn't just died and you got the data
1619intact. This is also one reason why so many internet protocols have an
1620explicit QUIT command.
1621
1622=item I don't want to destroy the handle too early - how do I wait until
1623all data has been written?
1624
1625After writing your last bits of data, set the C<on_drain> callback
1626and destroy the handle in there - with the default setting of
1627C<low_water_mark> this will be called precisely when all data has been
1628written to the socket:
1629
1630 $handle->push_write (...);
1631 $handle->on_drain (sub {
1632 warn "all data submitted to the kernel\n";
1633 undef $handle;
1634 });
1635
1636=back
1637
1638
1456=head1 SUBCLASSING AnyEvent::Handle 1639=head1 SUBCLASSING AnyEvent::Handle
1457 1640
1458In many cases, you might want to subclass AnyEvent::Handle. 1641In many cases, you might want to subclass AnyEvent::Handle.
1459 1642
1460To make this easier, a given version of AnyEvent::Handle uses these 1643To make this easier, a given version of AnyEvent::Handle uses these

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